Structural studies on new metal derivatives of osteoporosis therapeutic aminohydroxyalkylidenebisphosphonic acids with C4 and C6 aminoalkyl chains

Hydrothermal reactions between the bisphosphonic acid 6-amino-1-hydroxy-1,1-hexylidenebisphosphonic acid and divalent hydrated metal nitrates of cobalt, nickel or zinc, in 1:0.75 molar ratio, afforded 1:2 mononuclear dichelate products Co 1, Ni 2 and Zn 3. Similar reactions using manganese or cadmium gave the 1:2 dinuclear products Mn 4 and Cd 5 with chelate bridging as well as chelate terminal bisphosphonate ligands. In contrast to mononuclear 1 the reaction between 4-amino-1-hydroxy-1,1-butylidenebisphosphonic acid and hydrated cobalt(II) nitrate gave a dinuclear product 6. The single-crystal X-ray structures of compounds 1–6 are discussed. The C6 alkylammonium chains in dinuclear compounds 4 and 5 display interesting supramolecular structure directing effects which are different from those in related compounds with C4 alkylammonium chains.

Hydrothermal reactions between the bisphosphonic acid 6-amino-1-hydroxy-1,1-hexylidene bisphosphonic acid and divalent hydrated metal nitrates of cobalt, nickel or zinc, afforded mononuclear dichelate products. Similar reactions using manganese or cadmium gave dinuclear products with chelate bridging as well as chelate terminal bisphosphonate ligands. The reaction between 4-amino-1-hydroxy-1,1-butylidene bisphosphonic acid and hydrated cobalt nitrate gave a dinuclear product. The C6 alkylammonium chains in dinuclear compounds display supramolecular structure directing effects which are different from those in related compounds with C4 alkylammonium chains.Figure optionsDownload as PowerPoint slide